1. Chapter 17 Immunoregulation

2. Chapter 17 Immunoregulation
The ability of the immune system to control and regulate its own responses is called immunoregulation.

3. To keep the individual homeostasis by regulating the balance between immunocyte and immunocyte, between immunocyte and immune molecule, and between immune system and nerve system /endocrine system.

4. Contents PartⅠ Immunoregulation on genetic level
PartⅡ Immunoregulation on molecular level
PartⅢ Immunoregulation on cellular level
PartⅣ Immunoregulation on individual and mass level

5. PartⅠ Regulation on genetic level
Immune response of individual controled by hereditary background:
Genes encode TCR and BCR
Genes encode molecules regulating immune response: MHC ?

6. PartⅡ Regulation on molecular level
Regulation of Ag
Regulation of Ab
Regulation of Complement
Regulation of co-stimulator and receptor

7. 1. Regulation of antigen Origination stage of immune response:
Route of Ag entrance a individual
Dosage of Ag
Structural characteristic: antigen competition

8. 2. Regulation of antibody
Regulation of immune complex: IgM, IgG
Regulation of idotype-anti-idiotype network

9. 2. Regulation of antibody
Regulation of Ag-Ab complex to immune response-----Antibody feedback regulation
IgM ---- positive feedback regulation
IgG ---- negative feedback regulation

10. g
B cell

12. FcRⅡB

13. 2. Regulation of idiotypic networks
Idiotypic determinant or idiotype: a unique determinant on an antibody ,usually formed by one or more of the hypervariable regions.
Idiotypic determinant may be recognized as “foreign” in an individual, but they are usually present in quantities too low to induce self-tolerance.
Anti-idiotypic antibody: antibodies against idiotype of antibodies internal image of Ag

14. Y B
Ab2β
Ab2α

15. 3. Regulation of complements
Promote APC capture antigens:
CR1 receptor on APC capture C3b-Ag-Ab complex
Promote the activation of B cell:
CR1, CR2 on B cell

16. 4. Regulation of co-stimulator and receptor
T cell: B CD28, CTLA-4
B cell: CD40L CD40, FcRⅡB
5. Regulation of cytokines

17. PartⅢ Regulation on cellular level
Regulation of T cells:
Natural regulatory T cells(Treg): CD4+CD25+foxp3+
Th cell subset
Regulation of B cells
AICD (activation induced cell death)

20. The immunoregulation of T cell subsets
Th1 cells promote the cellular immunity suppressing the humoral immunity.
Th2 cells promote the humoral immunity suppressing the cellular immunity.

21. Th1
+IL-12
+IL-4
IL-2 IFN-g
IL-4 IL-10
inhibit
Cell mediated immunity
Humoral immunity
Th0
Th2
Interaction of Th1 and Th2

24. Regulation of T cell subset by different cytokines
T cell subset Representative cytokine
CD4+Th IL-2, IFN-γ
CD4+Th IL-4, IL-10
CD4+Th TGF-β
CD4+Th IL-17

25. Activation-induced cell death（AICD）
AICD: activated T or B cell apoptosis elicited by Fas(CD95)
Apoptosis of target cell :
FasL on Tc binds to Fas on target cells-----induce the apoptosis of target cell.
Apoptosis of activated T cells:
Fas is also expressed on activated Tc or B cell, so FasL on activated T cell binds to Fas on activated T cell or B cell, then induces activated T cells or B cell apoptosis.

27. (FasL)
(Fas)

28. Part IV Regulation on systemic level
Regulation of nerve-endocrine-immune system networks:
Nerve and endocrine regulate immune system.
Immune system regulate nerve and endocrine system.

29. Interaction of neuroendocrine system
and immune system
精神因素
中枢神经系统
松果体激素
免疫介质
内分泌激素
神经肽
内分泌激素
内分泌系统
免疫系统
免疫介质

30. Keep a good humor everyday !!!